Kiln



M. L. MUELLER May 6, 1930.

KILN

FiledMaich 12, 1929 :Q-INVENTOR. Worztz Z Weller,

ATTORNEYS Patented May 6, 1930 PATENT OFFICE MOBITZ L. MUELLER, OF SEATTLE, WASHINGTON KILN Application filed March 12, 1929. Serial No. 346,368.

This invention relates to kilns, and more particularly to lumber drying kilns, and it has for its object to provide an improved assemblage of thekiln structure and air distributing instrumentalities, by virtue of which important functional and economic advantages arev secured.

In the accompanying drawing, Fig. 1 is a transverse vertical sectional To view of a kiln,constructed in accordance with theinvention, and v Fig. 2 is a longitudinal sectional view through the air delivery duct, hereinafter described.

Like numerals designate corresponding parts in both of the figures of the drawing. In the drawing, 5 designates a body or housing constituting the wall of the kiln. This kiln is preferably provided with rails 6, upon which trucks 7, loaded with lumber 8, may be run into the kiln. Circulation of dryin'g air may beset up transversely within the kiln by means of anexternal fan 9, that is mounted upon the top of the kiln, and which receives its air supply from a suction duct 10, that is in communication with a longitudinally extending suction duct 11. The air enters this suction duct at points in its under side, adjacent the wall of the kiln, 3.9 as indicated at 12. The airwhich passes from the suction duct 10 to the fan is suitably conditioned in any desired way, as, for example, by being passed over steam pipes 13 to be heated, or by having steam discharged thereinto from jet 14, for humidifying the same. A fresh air intake door is indicated at 16,

through which desired quantities of fresh" air may be admitted to the circulating stream of air within the kiln. The air is discharged I have claimed the method of bringing about a lateral diffusion of air within'a kiln without resorting to mechanical deflectors, by dis= from the fan casing 9, into a discharge or charging a stream of hot air downwardly be-- tween the side wall of the kiln and a pile of flat piled lumber, having lateral passages between the courses of the same, the lateral diffusion being brought about by the tendency" of the heated air to start to rise after'it has lost the momentum initially imparted thereto by the fan or blower.

The apparatus illustrated and described in this application iswell adapted to carry out the method of the application aforesaid. The fan 9 initially discharges the heated air downwardly with considerable momentum,- as indicated by the arrows a. When. the air loses its momentum, it tends to rise again and the creation of these conflicting forces,

that is, a downwardly moving and: an upwardly moving current of air in the relatively restricted space between the side wall of the kiln and the pile of lumber, brings about such lateral diffusion of the air as causes it to move freely through the channels in the pile of lumber, and in the manner indicated by the arrows. The arrows 0 indicate that some of the air in the upper portion of the kiln will be-drawn into the downwardly moving current of air from duct 17 thus, more air is circulated than is actually handled by the fan. In addition to the advantages inherent'in the lateral diffusion of the air, as described above, the arrangement herein shown and described has the. advantage that it is much cheaper to build than the ordinary types of kilns, wherein the fans and ducts are located at the bottom of the kiln,because it is not necessary to construct a basement for the kiln.

Further,the-fans and ducts are not subjected to the fall of water and saw-dust thereon, as in certain other types of kilns now largely used. In addition, no condensation 'on the ceiling of the kiln takes place, because of the air travel in close proximity thereto.

It will be seen that the air is drawn from every part of the kiln chamber, reconditioned, and returned thereto. Thus, no fixed localized conditions can remain in existence.

It is to be understood'that the invention is not limited to the preciseconstruction set forth, butthat it includes Within its purview Whatever changes fairly come within either the terms or the spirit of the appended claims. a e 7 Having described my invention, what I claim is: 1

1. The combination with a kiln having a trackway therein for the reception of loads e of lumber fiat piled in spaced courses, of a continuous longitudinally extending discharge duct in one upper corner: thereof, having a series of equi-distantly spaced discharge orifices extending substantially throughout its length and substantially throughout the length of the kiln, a suction duct'in the other upper corner of thekilnaa housing upon the derside of the said pressure duct lying such a material distance above the lumber as to cause the jets dischargeddownwardly there from to f draw. induced air from the space above said liumber into the air stream.

2. The combination with akiln, of a continuously longitudinally extending iduct in each upper corner=thereof, one of which constitutes the suction duct and'the other of which constitutes the pressure duct,a housing upon thetop of the kiln with which'the suction duct communicates, heating means for air in-said housing,a fan casing connected tosaid-housing, a fan-1n said casing discharging directly transversely of the-kiln, the discharge side of 'said fan beingconnectedto the pressure. duct, and controlling deflectors past which air is discharged from the pressure ductsubstantiallystraight downwardly and directly al'ong the side wall of the kiln at all points in the length of the kiln, V the undersides of the said ducts being spaced such a material distance above the lumber that the air discharged downwardly therefrom acts 7 toinduce-movement of; the air from above the lumber into the-air stream.

03. lhe combination with a ki1n,-of a continuously longitudinallyextending duct in each-uppercorner thereof, one of which constitutes the suction duct and the other of i which constitutesthe pressure duct, a'housing upon-the top ofthe kiln with whichthe suction-.duct communicates, conditioning means for air in said-housing, a fan casing; connected to said housing, a fan in said casing discharging directlytransversely ofjthe kiln,-the discharge side. ofsaid fan b'eing- 'c0nnected to said pressure duct, and controlling deflectors past which airis discharged from the pres- I sure duct straightdownwardly and directly a 4. The combination with a kiln, of a continuously longitudinally extending duct in each upper corner thereof, one of which can stitutes the suction duct and the other of 'which' constitutes the pressure duct, a housing upon the top of the kiln with which the suction duct communicates, heating means for air in said housing, a fan casing connected to said housing, a' fanin saidcasing discharging directly transversely of the kiln, the discharge 7 side of said fan being connected to said pressure duct, and controlling; deflectors past which air is discharged from the pressure duct straight downwardly along the side wall of the kiln in substantially equal volume at all points in the length of the kiln, and'means for drawing fresh air into said housing exteriorly of the kiln, the-undersides of the said ducts being spaced such a material distance above the lumber that the air discharged downwardly therefrom acts to induce move: ment of air from above the lumber into the air'stream. Q i 5. The combination witha kiln, of a continuously longitudinally extending duct in each upper corner thereof, one of which constitutes the. suction duct and 'theother of which constitutes the pressure d'uct, a housmg upon the top of'the kil'n with which the suction duct communicates, heating, means for airlin said housing, a fan casing connected to-said housing, a fan in said casing discharging directly transversely of the kiln, the discharge side of said'fan being connected to said pressure duct, controlling deflectors past which air is discharged from the pressure duct straight downwardly along the side wall of the kiln in substantially equal volume at all points in the length of the kiln, means for drawing fresh'air into said housing exteriorly of'the kiln, and means for discharging the vapors from the top of said kiln, the undersides oflthe saidducts being spaced such a material distance above the lumber that the air discharged downwardly therefrom acts to induce movement of air from above'the lumber intothe air stream. v

6.' Thecombination with a kiln having a trackway therein for the reception of lumber trucks having lumber flat piled in spaced courses thereon, the construction and the width of the kiln being such that when such trucks of lumber are placed in the kiln, the spaces between the lumber and the side walls of the kilnwill be relatively narrow and vertically unobstructed, a duct in each upper cornor of the kiln and above such relatively narrow spaces, one of which constitutes a suction duct and the other of which constitutes a pressure duct, said ducts extending continuously longitudinally of the kiln and respecoutside of the kiln and upon the top thereof and connecting the suction and pressure ducts and air circulating means in said housing, outside the kiln of such nature as to draw air'from the suction duct and discharge it directly transversely of the kiln into the pres sure duct, the under side of the said pressure,

duct lying such a material distance above the lumber as to cause the jets discharged downwardly therefrom to draw induced air from the space above said lumber into the air stream.

In testimony whereof I aflix my signature.

MORITZ L. MUELLER.

7. The combination with a kiln having a trackway therein for the reception of lumber trucks having lumber fiat piled in spaced courses thereon, the construction and the width of the kiln being such that when such trucks of lumber are-placed in the kiln, the

spaces between the lumber and the side walls of the kiln will be relatively narrow and vertically unobstructed, a duct in each upper corner of the kiln and above such relatively narrow spaces, one of which constitutes a suction duct and the other of which constitutes I p a pressure duct, said ducts extending continuously longitudinally of the kiln andrespectively taking in and discharging air at points substantially directly above and in a straight line downwardly into such narrow spaces. at all points in the length of the kiln, a transverse housing at the top of the kiln connecting said ducts, a fan in said housing, and heating means in said housing, said housing, fan and heating means being located outside of and upon the top of the kiln, said fan discharging directly transversely of the kiln, and the undersides of the said ducts being spaced such a material distance above the lumber that the air discharged downwardly therefrom acts to induce movement of air from above the lumber into the air stream. 7

8. The combination with a kiln having a trackway therein for the reception of loads of lumber flat piled in spaced courses and wherein the width of the kiln, with respect to the width of the piles of lumber, is such that relatively narrow spaces are left between the sides of the piles of lumber and the side of the kiln, of a pressure duct in one upper" corner of the kiln of a width greater than the width of the space between the side of the kiln and the pile of lumber therebeneath, said pressure duct extending substantially throughout the length of the kiln and having a large number of relatively closely spaced discharge orifices in that portion of its bot-' tom nearest the side wall of the kiln, a suction duct in the opposite upper corner of the kiln having its intake point adjacent the side wall of the kiln, a transverse housing disposed 

